Structural Build - up of Rigid Fiber Reinforced Cement - Based 1 Materials

15 The structural build-up of rigid fiber reinforced cement-based materials is studied. It has 16 recently been shown that the behaviour of fiber reinforced concrete depends on the orientation 17 of the fibers that has to be optimized during casting. As a result, there is a great interest to 18 study the rheology of fiber reinforced concrete. One of the most important characteristic of 19 modern fresh concretes is the structural build-up which is involved in many recent issues of 20 concrete casting. This characteristic depends on the cement pastes chemical activity. This 21 present work shows that structural build-up modelling used for common concretes can be 22 generalized to fiber reinforced concretes. It can be shown that, if the inclusions percolation 23 threshold is not reached, the structural build-up rate A thix is amplified by the addition of fibers 24 and aggregates. Finally, this amplification of the structuration is estimated using modelling 25 initially developed for spherical inclusions and aggregates.